AmlodipineCalcium Channel BlockersAntihypertensive AgentsDihydropyridinesTetrazolesHydrochlorothiazideHypertensionAzetidinecarboxylic AcidValineDrug Therapy, CombinationBlood PressureDouble-Blind MethodChlorthalidoneNifedipineLisinoprilAngiotensin II Type 1 Receptor BlockersMibefradilTreatment OutcomeAtenololCross-Over StudiesBenzimidazolesAngiotensin-Converting Enzyme InhibitorsDrug CombinationsDiuretics